The three David doors of Japanese porcelain are Imari, Suihu and Youtian. Imari porcelain is famous for its exquisite painting and decoration, Suihu porcelain is famous for its simple and practical style, and Youtian porcelain is famous for its exquisite craftsmanship and high-quality porcelain. The porcelain production techniques and styles in these three places have their own characteristics, and the isomorphism of * * * has become a rich diversity of Japanese porcelain.